This invention relates generally to the field of collapsible large size shipping containers, of a type, for example, disclosed in my copending application, Ser. No. 941,149 filed Sept. 4, 1978, under the title, "Collapsible Shipping Container Construction," and more particularly to an improved form of synthetic resinous clip adapted to perform the joint functions of closing the lid upon a main body of the container, and effecting a seal which prevents removal of the clip until the seal is breached, thereby providing a means for indicating the presence of tampering.
The problem of pilferage of large shipping containers is well known, irrespective of the form of transportation employed. Where the shipping containers are formed of relatively lightweight materials, such as heavy-grade corrugated board, it has been common practice to provide a seal-retaining means in the form of a metal stamping which is engaged upon an inner edge of a main body portion of the container, and which projects through an opening in the lid to be engaged by a frangible seal. To remove the lid from the main body of the container, it is necessary to destroy the seal. In the case of an unauthorized opening, the presence of tampering is immediately revealed.
To facilitate a rapid and convenient securing of the lid upon the container, there have already been developed in the art a plurality of expandable type clips, usually formed of molded synthetic resinous materials which are of an overall expanded size and configuration corresponding to a pair of alignable openings in portions of the lid and the main body of the container. When the container is closed by placing the lid in position, openings in the lid and container are thereby aligned, and the expandable clip is inserted in unexpanded condition to be thereafter expanded to grip the edges of the openings in both parts of the container, and maintain such parts in abutted relation. In one form of clip, there are two separable elements, one of which fits into the other to expand the outer element to the above-described condition. Another type is formed integrally to include a pair of sections foldable about a transversely extending fold line to move the clip between contracted and expanded conditions. Neither clip has provision for sealing the clip in expanded condition, and, as illustrated in my above-mentioned copending application, a separate seal-retaining means is required. This requirement, in turn, requires the cutting of additional openings for the seal-retaining means, and, of course, the added expense of the forming of the seal-retaining means which, while reusable, is not inexpensive to manufacture.